The protein encoded by this gene is an adaptor molecule that interacts with various cell surface receptors and mediates cell apoptotic signals. Through its C-terminal death domain, this protein can be recruited by TNFRSF6/Fas-receptor, tumor necrosis factor receptor, TNFRSF25, and TNFSF10/TRAIL-receptor, and thus it participates in the death signaling initiated by these receptors. Interaction of this protein with the receptors unmasks the N-terminal effector domain of this protein, which allows it to recruit caspase-8, and thereby activate the cysteine protease cascade. Knockout studies in mice also suggest the importance of this protein in early T cell development. [provided by RefSeq, Jul 2008],